Exclusive<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>ρ</mml:mi></mml:math>Production by Virtual Photons

Abstract

The cross section for production of ${\ensuremath{\rho}}^{0}$ mesons has been measured in the reaction $e+p\ensuremath{\rightarrow}e+p+{\ensuremath{\pi}}^{+}+{\ensuremath{\pi}}^{\ensuremath{-}}$. The cross section is presented as a function of $W$, the c.m. energy of the virtual-photon-proton system, and -${Q}^{2}$, the square of the virtual-photon mass. The vector-dominance model is not able to describe the dependence of the cross section on the parameters ${Q}^{2}$ and $W$. The slope parameter $B$ describing the scattering of the proton exhibits a significant variation with ${Q}^{2}$.